1. Field of the Invention
This invention relates to new and improved telephone line security systems, and more particularly to telphone line security systems that prohibit outgoing telephone calls to telephone numbers containing certain combinations of digits.
2. Description of the Prior Art
It is well known in the art of telephony that restricting the capacity of a telephone instrument to complete telephone calls to telephone numbers having excessive length enhances the security of the telephone lines. Additionally, it is well known in the art of telephony that restricting the capacity of a telephone instrument to complete telephone calls to telephone numbers having specified first digits enhances the security of the telephone line.
Additionally, it is well known in the art of telephony that use of a code access number that aviods activation of the restrictions on the capacity of a telephone instrument to complete telephone calls to telephone numbers having specified first digits enhances the security of the telephone line.
Additionally, it is well known in the art of telephony to place the device that causes activation of the restrictions on the capacity of a telephone instrument to complete telephone calls to telephone numbers having specified first digits either in the telephone instrument or in series connection between the telephone instrument and the telephone switching center.
The patents provided in the prior art statement submitted herewith illustrate the state of the art in telephone line security systems that prohibit outgoing telephone calls to telephone numbers containing prohibited combinations of digits.